The principal objective of the Geisinger Clinical Oncology Program is to enroll a maximum number of participants onto NCI-approved cancer prevention, cancer control and cancer treatment protocols, bringing research-quality cancer care to a large rural population of Pennsylvania. The Geisinger Health System serves more than 2.3 million Pennsylvanians across 31 primarily rural counties in the central and northeastern parts of the state. This Health System includes a 535 physician primary and multispecialty group practice in 45 sites, anchored by the 437 bed tertiary care Geisinger Medical Center in Danville, the largest rural tertiary center in the U.S. The other major hubs of the System are in State College (90-member multispecialty group) and Wilkes-Barre (160 bed hospital with 100-member multispecialty group). These hubs will each be an important CCOP site as well. Geisinger Health system operates a staff model HMO with nearly 300,000 members that works cooperatively with the CCOP to promote cancer prevention trials. Among Geisinger's advantages are a stable and growing CCOP staff with a history of excellent retention of personnel and with successful performance over the 19 year history of the NCI CCOP program. The system enjoys a large network of primary care practices, with all practices and all physicians (including specialists) linked by a state-of-art electronic medical record (EPIC-Care), and a large cancer patient population (over 2000 new analytic cases/year). The addition of new System C.E.O. Dr. Glenn Steele, a prominent academic surgical oncologist and researcher, has given new emphasis to the institutional commitment to growing cancer research. The System has been reorganized into Service Lines, which has greatly aided the Cancer Service Line, Geisinger Cancer Institute, in recruiting and building in all three major hub sites. Clinical trial performance is enhanced by a new computerized clinical protocol management system (Protonet), a System-wide cancer registry that includes all outpatient as well as all hospital sites, and the computerized medical record with interlocked laboratory, radiology, demographics, appointments and on-line digital images. Recruiting participants onto prevention trials has been helped by direct recruiting by Geisinger's HMO, which is clinical research friendly, seeing such activities as part of its primary health promotion mission. This proposal retains NCCTG as the primary research base, ECOG as a secondary base, COG as our children's base, and GOG (MD Anderson affiliation) as a separate gynecologic base.